Derrick



A. COLBY.

(No Model.)

DERRICK.

No. 448,321. Patented Mar. 1'7, 1891.

llnrTEn STATES PATENT EEIcE.

ALLEN COLBY, OF BRUNSIVIGK, MAINE DERRICK.

SPECIFICATION forming part of Letters Patent No. 448,321, dated March17, 1891.

Application filed October 25, 1890. Serial No. 369,291. (No model.)

To all whom it may concern.-

Be it known that I, ALLEN COLBY, a cit zen of the United States,residing at Brunswick, in the county of Cumberland and State of Maine,have invented certain new and useful Improvements in Derricks; and I dohereby declare the following to be a full, clear, and exact descriptionof thein vention, such as will enable others skilled in the art to whichit appertains to make and use the same.

My invention relates to derricks for raising and moving heavy articlesfrom one place to another; and it is designed particularly for loadingand unloading cars.

In carrying out my invention I build an elevated track, which extendsover one or more of the car-tracks, and on this elevated track runs atraveler. The traveler has a Windlass which operates a fall, the fallpassing through a system of purchase-blocks and sheaves, by which thepower of the Windlass is greatly increased. Fora fall I make use of achain, which passes over a sprocket-wheel on the Windlass and is held inplace on said sprocket-wheel by means of a guide-pulley, which ispivoted adjacent to the drum and holds the chain in contact with thedrum. The traveler is moved on its track by means of a chain which issecured at the extremities of the track and passes over a sprocket-wheeloperated by a Windlass.

I have illustrated my invention by means of the accompanying drawings,in which- Figure 1 is a section on the line x mot Fig. 2, and Fig. 2 isa plan or top view.

A represents an elevated track supported 011 posts a a. This track isbuilt of sufficient length to extend over the space within which thederrickis to operate. Forinsta11ce,forrailroad-work it would extendacross one or more of the railroad-tracks and over the platform or spacewhere the teams are to stand while being loaded. Running 011 thiselevated track Ais a traveler B, supported by trucks b. This traveler isbuilt of any desired shape to accommodate the various bearings necessaryfor the windlasses and purchase-blocks. The hoisting-gear is operated bya Windlass of which 0 is the gear and I) the pinion, cl the crank-shaft,and cl the crank. On the main shaft 0 is a sprocket wheel or drum chaving a groove in its periphery which receives and holds the chain G,which is used for a fall. A pawl or dog 0 is provided to engage the gearC. To prevent any possibility of the chain slipping, I provide aguide-pulley 0 immediately beneath the sprocket-wheel e the perimetersof the two wheels coming near together with just room enough for thechain to pass between them. The chain is thus held continually incontact with the sprocket wheel, and is thus prevented from working outand slipping. A box F is placed under the Windlass to receive the chain.

I get my purchase in the derrick, as here shown, by means of a doublepurchase-block K and two sheaves ee, mounted on the frame of thetraveler. The block K has two sheaves 7c and 7a, pivoted one over theother. The fall passes through the block and over the fixed sheaves, andits end is secured, as here shown, to the block K. A hook is secured tothe block for convenience in hooking onto various articles.

Means are provided for moving the traveler along the track. For thispurpose I make use of a Windlass, of which IL2 is the crank, '1; thecrank-shaft, I the pinion, II the gear, h the main shaft, and h thedrum, which is formed like a sprocket-wheel to receive the chain .I andhold it. The chain J passes over the pulleys 7L2, mounted at the lowerpart of the traveler in a bracket. The chain J extends in eachdirection, and each end is secured to a stud or similar piece j at theend of the track. It is obvious that by working the Windlass II I thetraveler is carried in either direction.

The operation of my device will be readily seen from its construction.

One man operating by means of my derrick can readily handle the heaviestarticles in loading and unloading cars and doing similar work. Havingraised the weight with one Windlass, he moves the traveler t0 thedesiredposition by means of the other and there deposits it.

The device is, as explained, admirably adapted for the use of railroadswhere heavy freight is to be handled.

I claim- 1. In a derrick, an elevated track, a traveler running thereon,a Windlass on said traveler having a sprocket-drum, a chain running 0ndWindlass B, having a sprocket-d rum,and' a chain running over said drumand over suitable gniding-pulleys and secured at its ends to theextremities of the said track, whereby said traveler may be moved onsaid track, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ALLEN COLBY.

Witnesses:

WILBUR F. LUNT, S. V. BATES.

